JP7397991B2 - electronic control unit - Google Patents

Description

The present invention relates to an electronic control device.

2. Description of the Related Art In recent years, electronic control devices used in automobiles include printed circuit boards on which semiconductor devices and the like are mounted. In an ECU (Electronic Control Unit) for automatic driving, as the automatic driving level increases, it is necessary to communicate and process a large amount of data at high speed. This ECU processes image data and signal data obtained by cameras, radars, etc., and sends signals to other ECUs that control power steering, brakes, etc. In this case, circuit specifications such as the amount of information transmission or SoC (System on Chip) function requirements vary depending on the type and function of the vehicle, so the circuit board tends to become larger.

Therefore, in order to meet various demands and suppress the increase in the size of circuit boards, technology for connecting multiple boards using connectors called BtoB (Board to Board) connectors has been adopted in various fields. An example of such a technique is the technique described in Patent Document 1, for example.

Japanese Patent Application Publication No. 2012-175032

On the other hand, the in-vehicle space where an ECU for autonomous driving of a vehicle can be placed is limited. For this reason, electronic control devices used in automobiles are required to have both smaller casings and improved heat dissipation. In the technique described in Patent Document 1, an electronic control device is constructed by stacking a plurality of substrates. Therefore, the height dimension of the electronic control device becomes large. Furthermore, since the amount of heat generated by the SoC increases depending on the throughput of the SoC, natural air cooling is insufficient and a fan must be provided. In the technology described in Patent Document 1, there is still room for consideration regarding optimization of the structure when a fan is arranged.

An object of the present invention is to provide an electronic control device that can achieve both miniaturization and improved heat dissipation.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above-mentioned problems, but one example is a first structure in which a heat dissipation fin is formed on one side and an electronic component that generates the largest amount of heat is thermally contacted on the other side. The present invention is an electronic control device including a casing having a second region on one side and a second region in which electronic components are in thermal contact with each other on one side and the other side.

According to the present invention, it is possible to achieve both miniaturization of an electronic control device and improvement in heat dissipation.
Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

FIG. 1 is a perspective view schematically showing the appearance of an electronic control device according to a first embodiment. FIG. 2 is an exploded perspective view of the electronic control device according to the first embodiment, viewed from above. FIG. 2 is an exploded perspective view of the electronic control device according to the first embodiment, viewed from below. FIG. 1 is a partial cross-sectional view of the electronic control device according to the first embodiment. FIG. 7 is a sectional view showing main parts of an electronic control device according to a second embodiment. FIG. 7 is a perspective view showing main parts of an electronic control device according to a third embodiment. FIG. 7 is a sectional view showing main parts of an electronic control device according to a fourth embodiment. FIG. 7 is an exploded perspective view of the electronic control device according to the fifth embodiment, viewed from below. FIG. 7 is a cross-sectional view showing main parts of an electronic control device according to a fifth embodiment. FIG. 7 is a bottom view showing the configuration of a first substrate included in an electronic control device according to a sixth embodiment. FIG. 7 is a bottom view showing the configuration of a first substrate to be compared with the sixth embodiment.

Embodiments of the present invention will be described in detail below with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

<First embodiment>
FIG. 1 is a perspective view schematically showing the appearance of an electronic control device according to a first embodiment. Further, FIG. 2 is an exploded perspective view of the electronic control device according to the first embodiment viewed from above, and FIG. 3 is an exploded perspective view of the electronic control device according to the first embodiment viewed from below.

As shown in FIGS. 1 to 3, electronic control unit 100 is, for example, an electronic control unit (ECU) used in an automobile. The electronic control device 100 includes a housing 11, a first board 21, a second board 22, a third board 23, a first cover 41, a second cover 42, and a fan cover 52. , is equipped with. The first board 21, the second board 22, and the third board 23 are circuit boards (printed boards) each having a wiring pattern. The second board 22 corresponds to a motherboard, and the first board 21 and the third board 23 each correspond to a daughter board. In this way, by dividing the first board 21, the second board 22, and the third board 23 into independent circuit boards, it is possible to use one or two boards depending on the type of automobile or the difference in function. can be changed flexibly. Although FIGS. 1 and 2 show an example in which the second substrate 22 and the third substrate 23 are divided, the present invention is not limited to this, and for example, the second substrate 22 and the third substrate 23 are divided. The substrate 23 may be composed of one substrate, or the number of divided substrates may be increased to three or more.

In addition, in this embodiment, the side where the first cover 41 is arranged as viewed from the casing 11 will be described as the upper side, and the side where the second cover 42 is arranged will be described as the lower side. ) and the left-right direction (horizontal direction) may change depending on the orientation of the electronic control device 100 when the electronic control device 100 is mounted on a vehicle.

(Case 11)
The housing 11 is made of a metal material such as aluminum or aluminum alloy. Therefore, the housing 11 has electrical conductivity and thermal conductivity. The housing 11 has a first area 111 and a second area 112. In this embodiment, as an example, the first region 111 and the second region 112 are divided in the longitudinal direction X of the housing 11. That is, in the present embodiment, the first region 111 and the second region 112 are divided with the approximate center of the housing 11 in the longitudinal direction X as a boundary. However, the boundary separating the first area 111 and the second area 112 can be arbitrarily set within the housing 11. Further, the housing 11 may have a predetermined area in addition to the first area 111 and the second area 112.

A radiation fin 61 is formed in the first region 111 of the housing 11 . The radiation fin 61 is a plate-shaped fin formed on the upper surface side (one side) of the first region 111. The radiation fins 61 are preferably formed integrally with the housing 11. A peripheral wall 12 is formed on the outer periphery of the housing 11 . The peripheral wall 12 includes a first peripheral wall 12 a formed on the upper surface side of the housing 11 and a second peripheral wall 12 b formed on the lower surface side of the housing 11 . The first peripheral wall 12a projects upward from the top surface of the housing 11, and the second peripheral wall 12b projects downward from the bottom surface of the housing 11.

Two holes 15 and 16 are formed in the housing 11. Each of the holes 15 and 16 is a hole through which a BtoB connector 32, 33 is inserted, in order to electrically connect the first board 21 and the second board 22 by BtoB connectors 32, 33, which will be described later. That is, each hole 15, 16 is a hole for connecting a connector. Each of the holes 15 and 16 is formed to penetrate the housing 11 in the thickness direction (vertical direction). Each hole 15, 16 is formed into a rectangle in plan view. At least one of the holes 15 and 16 is formed so that the longitudinal direction of the hole is substantially parallel to the X direction, which is the arrangement direction of the first region 111 and the second region 112. In this embodiment, as an example, the longitudinal direction of the hole 15 is approximately parallel to the arrangement direction of the first region 111 and the second region 112.

(First board 21)
The first board 21 is a board fixedly mounted on the upper surface side of the casing 11. The first substrate 21 is arranged in the first region 111 of the housing 11 at a position adjacent to the radiation fins 61 . As shown in FIG. 3, two electronic components 25 are mounted on the lower surface of the first substrate 21 using a BGA (Ball Grid Array). "Mounted by BGA" means "surface mounted using solder balls." The electronic component 25 is an electronic component that generates less heat than the electronic component 26 described later. The electronic component 25 is, for example, an image processing SoC (System on Chip). As shown in FIG. 4, the electronic component 25 is arranged so as to be in contact with the upper surface of the housing 11 via the heat dissipation material 72. Thereby, the electronic component 25 is in thermal contact with the housing 11 on the upper surface side of the second region 112. Therefore, heat generated by the electronic component 25 during high-speed communication is transmitted to the housing 11 via the heat dissipation material 72. The heat dissipation material 72 is made of, for example, heat dissipation grease. Note that thermal contact refers to a state of contact in which heat can be smoothly transferred between two objects or two target parts.

In addition to the electronic component 25 described above, a connector half 32a of the BtoB connector 32 and a connector half 33a of the BtoB connector 33 are each mounted on the lower surface of the first board 21 using BGA. That is, the electronic component 25, the connector half 32a of the BtoB connector 32, and the connector half 33a of the BtoB connector 33 are mounted on the same surface of the first board 21 using BGA. The connector half 32a is a connector that has a male/female relationship with the connector half 32b of the BtoB connector 32 mounted on the second board 22, and can be mated with the connector half 32b. It is composed of That is, the BtoB connector 32 is composed of a connector half 32a and a connector half 32b. The connector half 33a is a connector that has a male/female relationship with the connector half 33b of the BtoB connector 33 mounted on the second board 22, and is configured to be able to fit into the connector half 33b. That is, the BtoB connector 33 is composed of a connector half 33a and a connector half 33b. Each of the BtoB connector 32 and the BtoB connector 33 corresponds to a first BtoB connector that electrically connects the first board 21 and the second board 22. Furthermore, a plurality of connectors 34 are mounted on the lower surface of the first board 21. Each connector 34 is a connector for communicating with the outside, and corresponds to a first connector.

(Second board 22)
The second board 22 is a board fixedly mounted on the lower surface side (the other side) of the housing 11. The first substrate 21 and the second substrate 22 are arranged so as to be stacked in the vertical direction, which is a direction perpendicular to the surface of each substrate. The second region 112 of the housing 11 is interposed between the first substrate 21 and the second substrate 22. Electronic components 24 are mounted on the upper surface of the second board 22 using BGA. The electronic component 24 is an electronic component that generates less heat than the electronic component 26 described later. The electronic component 24 is, for example, a PCIeSW (PCI Express Switch). The electronic component 24 is arranged so as to be in contact with the lower surface of the casing 11 via a heat dissipating material (for example, heat dissipating grease) not shown. Thereby, the electronic component 24 is in thermal contact with the housing 11 on the lower surface side (the other side) of the second region 112. Therefore, heat generated by the electronic component 24 during high-speed communication is transmitted to the housing 11 via the heat dissipation material. Further, the second substrate 22 is arranged to face the first substrate 21 in the vertical direction, which is a direction perpendicular to the substrate surface. By arranging the first board 21 and the second board 22 in this manner, the horizontal dimensions of the entire electronic control device 100 can be kept smaller than when these boards are arranged side by side in the left-right direction. I can do it.

On the upper surface of the second board 22, in addition to the electronic component 24 described above, a connector half 31b of the BtoB connector 31, a connector half 32b of the BtoB connector 32, and a connector half 33b of the BtoB connector 33. Each is implemented by BGA. That is, the electronic component 24, the connector half 31b of the BtoB connector 31, the connector half 32b of the BtoB connector 32, and the connector half 33b of the BtoB connector 33 are mounted on the same surface of the second board 22 by BGA. has been done. The connector half 31b is a connector that has a male/female relationship with the connector half 31a of the BtoB connector 31 mounted on the third board 23, and is configured to be able to fit into the connector half 31a. That is, the BtoB connector 31 is composed of a connector half 31a and a connector half 31b. The BtoB connector 31 corresponds to a second BtoB connector that electrically connects the second board 22 and the third board 23. Of the connector half 31a and the connector half 31b constituting the BtoB connector 31, the connector half 31a is provided on the surface of the third board 23 on which the electronic components 26 are mounted, that is, the top surface of the third board 23. , the connector half 31b is provided on the surface of the second board 22 on which the electronic components 24 are mounted, that is, on the top surface of the second board 22. As a result, the second board 22 and the third board are aligned with the mounting surface of the electronic component 24 on the second board 22 and the mounting surface of the electronic component 26 on the third board 23 aligned in the same direction. 23 can be connected by the BtoB connector 31. On the other hand, the connector half 32b is fitted with the connector half 32a when the electronic control device 100 is assembled. The connector half body 33b is fitted with the connector half body 33a when the electronic control device 100 is assembled. Furthermore, a plurality of connectors 35 are mounted on the lower surface of the second board 22. Each connector 35 is a connector for communicating with the outside, and corresponds to a second connector. Here, the connector 34 provided on the first board 21 and the connector 35 provided on the second board 22 are arranged on the same side of the side surface of the case 11 in the transverse direction Y of the case 11. has been done. By arranging the connectors 34 and 35 in this manner, the connection directions (fitting directions) of the connectors (not shown) that have a male/female relationship with each of the connectors 34 and 35 can be aligned in the same direction. can.

(Third substrate 23)
The third substrate 23 is arranged on the same plane as the second substrate 22. The third substrate 23 is provided on the area where the radiation fins 61 are formed. The third board 23 is mounted on the lower surface side of the casing 11 together with the second board 22. An electronic component 26 is mounted on the upper surface of the third board 23 using BGA. The electronic component 26 is an electronic component that generates the largest (largest) amount of heat among the electronic components mounted on the first substrate 21, the second substrate 22, and the third substrate 23. The electronic component 26 is, for example, an accelerator (SoC for accelerator). The electronic component 26 is configured by a surface-mounted package (for example, a BGA package). The electronic component 26 is arranged so as to be in contact with the lower surface of the casing 11 via a heat dissipating material (for example, heat dissipating grease) not shown. Thereby, the electronic component 26 is in thermal contact with the housing 11 on the lower surface side (the other side) of the first region 111. Therefore, heat generated by the electronic component 26 during high-speed communication is transmitted to the housing 11 via the heat dissipation material.

In addition to the electronic component 26 described above, a connector half 31a of a BtoB connector 31 is mounted on the upper surface of the third board 23 using BGA. That is, the electronic component 26 and the connector half 31a of the BtoB connector 31 are mounted on the same surface of the third board 23 using BGA. The connector half body 31a is horizontally fitted into the connector half body 31b described above. Thereby, the second board 22 and the third board 23 are horizontally connected by the BtoB connector 31.

(First cover 41)
The first cover 41 is a cover provided to cover the opening on the upper surface side (one side) of the housing 11 in the vertical direction. The first cover 41 is attached to cover the first substrate 21 from the outside. The lower surface of the first cover 41 is arranged to face the upper surface of the first substrate 21 , and the upper surface of the housing 11 is arranged to face the lower surface of the first substrate 21 . Therefore, the first substrate 21 is arranged in the space formed by the housing 11 and the first cover 41 in the vertical direction. The first cover 41 is formed into a rectangular shape in a plan view with larger dimensions than the outer dimensions of the first substrate 21 so as to cover the entire area of the first substrate 21 . The first cover 41 is made of a metal material such as an iron alloy, and more specifically, a plated steel plate. By providing the first cover 41 on the electronic control device 100, the first cover 41 can prevent dust and the like from entering from the outside to the inside of the electronic control device 100, thereby suppressing the occurrence of contamination. Furthermore, by covering the first substrate 21 with the first cover 41, the first cover 41 prevents contact with the first substrate 21 from the outside, and protects the first substrate 21 from external damage. I can do it.

(Second cover 42)
The second cover 42 is a cover provided to cover the opening on the other side (lower surface side) of the housing 11 in the vertical direction. The second cover 42 is attached to cover the second substrate 22 and the third substrate 23. The upper surface of the second cover 42 is arranged to face the lower surfaces of the second board 22 and the third board 23, and the lower surface of the casing 11 is arranged opposite to the upper surface of the second board 22 and the third board 23. placed facing each other. Therefore, the second board 22 and the third board 23 are arranged in the space formed by the housing 11 and the second cover 42 in the vertical direction. The second cover 42 has a dimension larger than the outermost periphery of the second substrate 22 and the third substrate 23 in plan view so as to cover the entire area of the second substrate 22 and the third substrate 23. It is formed into a rectangle. The second cover 42 is made of a metal material such as an iron alloy, more specifically, a plated steel plate. By providing the second cover 42 on the electronic control device 100, the second cover 42 can prevent dust and the like from entering from the outside to the inside of the electronic control device 100, thereby suppressing the occurrence of contamination. Furthermore, by covering the second substrate 22 and the third substrate 23 with the second cover 42, the second cover 42 prevents the second substrate 22 and the third substrate 23 from coming into contact with the outside. The second substrate 22 and the third substrate 23 can be protected from external damage and the like.

(Fan cover 52)
The fan cover 52 is a cover provided to cover the radiation fins 61. The fan cover 52 has three openings 52a formed therein. The three openings 52a are ventilation openings and are formed to correspond to the three fans 51. The fan 51 is a fan for forced air cooling. The number of fans 51 can be changed as necessary. Further, the fan 51 may be provided as necessary, and the fan cover 52 may also be provided as necessary. The opening 52a serves as an intake port for taking air into the fan 51 from the outside of the electronic control device 100 when the fan 51 is driven. The fan 51 is provided on the fin side (top side) of the first region 111 of the housing 11 . Specifically, the middle portion of the upper surface of the first region 111 is formed into a groove having no fin structure, and the three fans 51 are arranged in a line in this groove. As a result, the fan 51 is arranged at the center of the heat radiation fin 61. The fan cover 52 is attached to the upper surface side of the housing 11 together with the first cover 41. The fan cover 52 is arranged adjacent to the first cover 41. The fan cover 52 is formed into a rectangular shape in plan view with dimensions matching the size of the radiation fins 61. The fan cover 52 is made of metal material.

When the fan cover 52 is attached to the top side of the housing 11 and the three fans 51 are driven, air is sucked into the fans 51 from each opening 52a, and the sucked air is radiated by the blowing function of the fans 51. It flows into the fin 61. As a result, an air flow is formed along the radiation fins 61. Therefore, the entire radiation fin 61 can be cooled. Furthermore, heat generated by the electronic component 25 during high-speed communication is conducted to the heat radiation fins 61 of the housing 11. Therefore, by cooling the radiation fins 61 with the fan 51, the heat generated by the electronic components 25 can be efficiently released to the outside of the housing 11. In addition, since the heat generated by the electronic components 26 during high-speed communication is also conducted to the radiation fins 61 of the housing 11, by cooling the radiation fins 61 with air by the fan 51, the heat generated by the electronic components 26 is transferred to the radiation fins 61 of the housing 11. can be efficiently released to the outside.

The electronic control device 100 having the above configuration is assembled, for example, in the following steps.
First, the connector half 31b mounted on the second board 22 and the connector half 31a mounted on the third board 23 are fitted together. Thereby, the second board 22 and the third board 23 are horizontally connected by the BtoB connector 31. Therefore, a large amount of data can be communicated at high speed between the second board 22 and the third board 23 through the BtoB connector 31.

Next, the second board 22 and the third board 23 are attached to the lower surface side of the casing 11. At this time, the connector halves 32b and 33b mounted on the second board 22 are placed inside the corresponding holes 15 and 16, respectively. Then, the second board 22 and the housing 11 are fastened together with screws 71 (see FIG. 1).
Next, the second cover 42 is attached to the lower surface side of the housing 11 so as to cover the second board 22 and the third board 23. At this time, the gap between the second cover 42 and the connector 35 and the gap between the second cover 42 and the housing 11 are each filled with a waterproof material 91 (see FIG. 1). By providing this waterproof material 91, it is possible to prevent water from entering the electronic control device 100 from the outside and protect the boards 21 to 23 inside the electronic control device 100.

Next, three fans 51 are attached to the upper surface side of the housing 11.
Next, the fan cover 52 is attached to the upper surface of the housing 11 so as to cover the radiation fins 61.

Next, the first substrate 21 is attached to the upper surface side of the casing 11. At this time, the connector halves 32a and 33a mounted on the first board 21 are placed inside the corresponding holes 15 and 16, respectively. Then, the first board 21 and the housing 11 are fastened together with screws 71 (see FIG. 1). Further, the connector half 32a is fitted into the connector half 32b, and the connector half 33a is fitted into the connector half 33b. Thereby, the first board 21 and the second board 22 are vertically connected by the BtoB connector 32 and the BtoB connector 33. Further, the connector halves 33a and 33b constituting the BtoB connector 33 are arranged within the space of the hole 16, and the connector halves 33a and 33b are connected to each other within this space. Although not shown, the connector halves 32a and 32b constituting the BtoB connector 32 are arranged within the space of the hole 15, and the connector halves 32a and 32b are connected to each other within this space.
In this way, by connecting the first board 21 and the second board 22 with the BtoB connector 32 and the BtoB connector 33, the BtoB connector is connected between the first board 21 and the second board 22. 32 and the BtoB connector 33, it becomes possible to communicate a large amount of data at high speed.

Next, the first cover 41 is attached to the upper surface of the housing 11 so as to cover the first substrate 21 . At this time, the gap between the first cover 41 and the connector 34 and the gap between the first cover 41 and the housing 11 are each filled with a waterproof material 91 (see FIG. 1). The reason for providing the waterproof material 91 is as described above.
This completes the assembly of the electronic control device 100.
Note that the procedure for assembling the electronic control device 100 is not limited to the procedure described above, and can be modified as appropriate.

(Effects of the first embodiment)
In the first embodiment described above, the radiation fins 61 are formed on one side of the upper surface, and the first region 111 is in thermal contact with the electronic component 26 that generates the largest amount of heat on the other side of the lower surface. The housing has a second region 112 on the upper surface side and the lower surface side with which the electronic components 24 and 25 are in thermal contact. Thereby, heat generated by the electronic component 26 that generates the largest amount of heat can be preferentially dissipated using the radiation fins 61. Of the electronic components 24 and 25 that do not generate as much heat as the electronic component 26, the electronic component 24 is brought into thermal contact with the lower surface of the housing 11, and the electronic component 25 is placed on the upper surface of the housing 11. By bringing them into thermal contact with each other, the heat generated by each of the electronic components 24 and 25 can be released to the housing 11.
Therefore, according to the first embodiment, it is possible to suppress the entire housing 11 from expanding in the lateral direction. In addition, regarding the vertical direction, the upper surface side of the first region 111 of the casing 11 is a single-layer region where the board is not stacked and mounted, and the radiation fin 61 is formed on the upper surface side of the first region 111, while the back side thereof The electronic component 26, which has a large amount of heat dissipation, is brought into thermal contact with the lower surface side of the first region 111 to radiate heat from the electronic component 26. Further, the second region 112 of the housing 11 is a laminated region where the first board 21 and the second board 22 are laminated and mounted, and the electronic components 24 and 25 are mounted in the second region 112. It is arranged in a concentrated manner. Therefore, efficient heat radiation can be achieved while downsizing the electronic control device 100. As a result, it is possible to achieve both miniaturization and improved heat dissipation of the electronic control device 100.

Further, in the first embodiment, the first substrate 21 is mounted on the upper surface side of the second region 112 of the housing 11, and the second substrate 22 is mounted on the lower surface side of the second region 112, which is the opposite side. are doing. As a result, when the first board 21 and the second board 22 are connected by the BtoB connectors 32 and 33, variations in the thickness of each board 21 and 22 can be absorbed by the connection portion of the BtoB connectors 32 and 33. I can do it. Thereby, variations in the thickness dimensions of the respective substrates 21 and 22 can be removed from the connection tolerance when connecting the first substrate 21 and the second substrate 22 using the BtoB connectors 32 and 33. Therefore, it is possible to narrow the clearance between the first substrate 21 and the second substrate 22, and it is possible to downsize the electronic control device 100 in the height direction (vertical direction). Furthermore, in the first embodiment, the first board 21 is fixed to the upper surface of the casing 11, and the second board 22 is fixed to the lower surface of the casing 11. This suppresses the displacement of the first substrate 21 with respect to the casing 11, and also suppresses the displacement of the second substrate 22 with respect to the casing 11. Therefore, the state of thermal contact between the second region 112 and the electronic component 25 and the state of thermal contact between the second region 112 and the electronic component 24 can be reliably maintained.

Further, in the first embodiment, the electronic component 26, which is an accelerator, and the connector half 31a of the BtoB connector 31 are mounted on the same surface (upper surface) of the third board 23 using BGA. Furthermore, the electronic component 24 which is PCIeSW, the connector half 31b of the BtoB connector 31, the connector half 32b of the BtoB connector 32, and the connector half 33b of the BtoB connector 33 are connected to the same surface ( mounted on the top surface). Furthermore, the electronic component 25 that is the image processing SoC, the connector half 32a of the BtoB connector 32, and the connector half 33a of the BtoB connector 33 are mounted on the same surface (lower surface) of the first board 21 by BGA. There is. In this way, by mounting each component on the board so that the mounting surfaces of the components (24, 25, 26, 31, 32, 33) to be mounted by BGA are all on the case 11 side, each component can be mounted on the board. On a board, BGA allows components to be mounted to be concentrated on one side. Therefore, there is no need to invert the board when each component mounted on the board by BGA is bonded to the board by the solder reflow method. Therefore, peeling of components from the substrate during solder reflow can be suppressed, and yield can be improved.

Further, in the first embodiment, the electronic component 26 mounted on the third board 23 is an accelerator, the electronic component 25 mounted on the first board 21 is the image processing SoC 25, and the electronic component 26 mounted on the third board 23 is an accelerator. An electronic component 24 mounted on 22 is a PCIeSW. Thereby, the heat generated by the electronic component 26, which is an accelerator, can be quickly transferred to the heat radiation fin 61. Further, heat generated by the electronic component 25, which is the image processing SoC, and the electronic component 24, which is the PCIeSW, can be transmitted to the heat radiation fins 61 through the housing 11, respectively.

Further, in the first embodiment, the longitudinal direction of the hole 15 for inserting the BtoB connector 32 is substantially parallel to the X direction, which is the arrangement direction of the first region 111 and the second region 112. Here, air exists inside the hole 15. The heat transfer coefficient of air is significantly lower than the heat transfer coefficient of the metal material (substantial part) that constitutes the housing 11. Therefore, if the longitudinal direction of the hole 15 is perpendicular to the X direction, the actual size of the casing 11 that contributes to heat transfer between the first region 111 and the second region 112 becomes narrower. On the other hand, when the longitudinal direction of the hole 15 is substantially parallel to the X direction, the actual size of the casing 11 that contributes to heat transfer between the first region 111 and the second region 112 is secured to be wide. be able to. Therefore, when forming the holes 15 in the housing 11, it is possible to suppress resistance to heat transfer due to the presence of the holes 15.

<Second embodiment>
Next, a second embodiment will be described.
FIG. 5 is a sectional view showing the main parts of the electronic control device according to the second embodiment.
As shown in FIG. 5, a recess 17 is formed on the upper surface of the second region 112 of the housing 11. The recess 17 is formed at a position where the electronic component 25 is placed when the first board 21 is attached to the housing 11. The recess 17 is formed in a rectangular shape along the outer shape of the electronic component 25, as shown in FIG. The depth dimension of the recess 17 is set according to the height dimension of the electronic component 25. The electronic component 25 is placed in the recess 17. Further, similar to the relationship between the recess 17 and the electronic component 25 described above, a recess 17 (see FIG. 3) is formed on the lower surface of the first region 111 of the housing 11, and the electronic component 26 is placed in the recess 17. Ru. Further, a recess (not shown) is also formed on the lower surface of the second region 112 of the housing 11, and the electronic component 24 is placed in this recess. In this way, by adopting a configuration in which each of the electronic components 24 , 25 , and 26 is arranged in the corresponding recess of the housing 11 , the thickness dimension of the housing 11 and the height dimension of the electronic control device 100 can be reduced. can be kept small.

Furthermore, as shown in FIG. 5, by adopting a configuration in which the gap formed between the recess 17 and the electronic component 25 is filled with a heat dissipating material 72, the electronic component The thermal contact area between 25 and the housing 11 is increased. Therefore, the heat generated by the electronic component 25 can be transmitted to the housing 11 with higher efficiency. Therefore, it is possible to further improve the heat dissipation effect. Such an effect can also be obtained when the gap between the recess (not shown) and the electronic component 24 is filled with a heat radiating material, or when the gap between the recess 17 and the electronic component 26 is filled with a heat radiating material.

<Third embodiment>
Next, a third embodiment will be described.
FIG. 6 is a perspective view showing main parts of an electronic control device according to a third embodiment.
As shown in FIG. 6, each fan 51 is arranged at an end of a radiation fin 61. As shown in FIG. Further, each fan 51 is arranged at an end of the casing 11 in the transverse direction Y. The lateral direction Y of the housing 11 is parallel to the longitudinal direction of the radiation fins 61. The end of the radiation fin 61 where the fan 51 is arranged is the upstream end in the direction in which cooling air flows when the radiation fin 61 is air-cooled by the air blown from the fan 51. In this way, when the fan 51 is arranged at the end of the radiation fin 61, the following advantageous effects are obtained compared to the case where the fan 51 is arranged at the center of the radiation fin 61 as shown in FIG. is obtained.

First, when the fan 51 is arranged at the center of the heat radiation fin 61, the heat radiation fin 61 is arranged on one side and the other side with the fan 51 at the center. Therefore, the air sent out by the fan 51 is divided into one radiation fin 61 and the other radiation fin 61 and flows therethrough. Therefore, on the upper surface side of the first region 111 of the housing 11, the air flows in two directions through the radiation fins 61. Further, the air flowing through the radiation fins 61 becomes wind containing heat emitted from the radiation fins 61, that is, hot air, and this hot air is discharged from both sides of the casing 11 in the transverse direction. The hot air discharged from the casing 11 may have an adverse effect on other electronic control devices mounted on the vehicle. Therefore, when the fan 51 is placed in the center of the heat dissipation fins 61, it is necessary to decide the mounting position of other electronic control devices in consideration of the influence of the hot air discharged from both sides of the casing 11 in the short direction. There are some layout constraints.

On the other hand, when the fan 51 is disposed at the end of the radiation fin 61, the air flowing through the radiation fin 61 by the fan 51 is directed in one direction. Therefore, the heat-containing air (hot air) emitted from the radiation fins 61 is emitted from only one side of the casing 11 in the short direction. Therefore, when the fan 51 is arranged at the end of the heat dissipation fin 61, the mounting position of other electronic control devices should be determined by considering only the influence of the hot air discharged from one side of the casing 11 in the short direction. I can do it. Therefore, when a plurality of electronic control devices are mounted on a vehicle, it is possible to increase the degree of freedom in layout.

In addition, in addition to the electronic components 24, 25, and 26 described above, if there is an electronic component (not shown) that generates significant heat, a radiation fin 61 is used to transfer the heat generated by this electronic component to the radiation fin 61. A recess (not shown) may be formed in the region where 61 is formed, and the electronic component may be placed within this recess. Thereby, the heat generated by the electronic components can be efficiently transferred to the radiation fins 61 and released to the outside. In addition, when forming a recess in the formation area of the radiation fin 61, by changing the shape and direction of the radiation fin 61 according to the arrangement of the electronic component, the recess in which the electronic component can be placed can be formed in the formation area of the radiation fin 61. can be secured.

<Fourth embodiment>
Next, a fourth embodiment will be described.
FIG. 7 is a sectional view showing main parts of an electronic control device according to a fourth embodiment.
As shown in FIG. 7, the electronic control device according to the fourth embodiment includes a heat pipe 85. The heat pipe 85 transfers heat generated by the electronic component 25 using a working fluid. The speed of heat transfer by the heat pipe 85 is faster than the speed of heat transfer by the metal material forming the housing 11. One end 85a of the heat pipe 85 is in thermal contact with the electronic component 25 via the heat dissipation material 72. The other end 85b of the heat pipe 85 is in thermal and physical contact with the radiation fin 61. Further, the other end portion 85b of the heat pipe 85 is inserted (fitted) into a through hole 115 provided in the housing 11 in the region where the radiation fins 61 are formed.

In the fourth embodiment, since the heat pipe 85 is provided which is in thermal contact with the electronic component 25 and the radiation fin 61, the heat generated by the electronic component 25 can be transferred to the radiation fin 61 at a high moving speed. . In addition, a through hole 115 is provided in the region where the radiation fin 61 is formed, and the heat pipe 85 is passed through the through hole 115, so that the heat pipe 85 is brought into thermal contact with the radiation fin 61. Therefore, by directly cooling the radiation fins 61 and the heat pipe 85 with the fan 51, the heat generated in the electronic component 25 can be efficiently released to the outside. Such an effect can be obtained even when a heat pipe is provided in thermal contact with the electronic component 24 and the radiation fin 61, or when a heat pipe is provided in thermal contact with the electronic component 26 and the radiation fin 61. can get.

<Fifth embodiment>
Next, a fifth embodiment will be described.
FIG. 8 is an exploded perspective view of the electronic control device according to the fifth embodiment viewed from below, and FIG. 9 is a cross-sectional view showing main parts of the electronic control device according to the fifth embodiment. In addition, in FIG. 8, the representation of the second board 22, the third board 23, and the second cover 42 is omitted.
As shown in FIGS. 8 and 9, in the electronic control device according to the fifth embodiment, the fan cover 52 is made of a metal material with high thermal conductivity, and the fins 52b are integrally formed on the fan cover 52. There is. The fins 52b are plate-shaped fins formed on the upper surface side of the fan cover 52, and allow heat to be released by natural convection. However, the fins 52b are not limited to plate-type fins, but may be pin-type fins. The fan cover 52 is bonded to the heat radiation fins 61 using a bonding material 82 such as a thermally conductive resin or heat radiation grease. The bonding material 82 is provided between the radiation fins 61 and the fan cover 52 by being applied to at least one of the tip surfaces of the radiation fins 61 and the lower surface of the fan cover 52 . As a result, the area where the radiation fins 61 are formed in the housing 11 comes into thermal contact with the fan cover 52 via the bonding material 82.

In the fifth embodiment, since the fins 52b are formed on the fan cover 52, the heat transmitted from each electronic component 24, 25, 26 to the radiation fin 61 is not only radiated from the radiation fin 61, but also It can also be released from the fins 52b of the fan cover 52. Therefore, the heat generated in each of the electronic components 24, 25, and 26 can be efficiently released to the outside.

<Sixth embodiment>
Next, a sixth embodiment will be described.
FIG. 10 is a bottom view showing the configuration of the first board included in the electronic control device according to the sixth embodiment, and FIG. 11 is a bottom view showing the configuration of the first board to be compared with the sixth embodiment. It is a bottom view.
In FIG. 10, two electronic components 25 mounted on the lower surface of the first substrate 21 are arranged with their positions shifted in the Y direction so that their positions do not overlap in the Y direction. In other words, the two electronic components 25 are arranged in parallel to the X direction. On the other hand, in FIG. 11, the two electronic components 25 are arranged at the same position in the Y direction so that their positions overlap in the Y direction. In other words, the two electronic components 25 are arranged in series with respect to the X direction.

Here, as described above, the X direction is the longitudinal direction of the casing 11, and is also the direction in which the first region 111 and the second region 112 are arranged. Further, a radiation fin 61 is formed on the upper surface side of the first region 111, and each electronic component 25 is in thermal contact with the upper surface side of the second region 112. Therefore, the heat transferred from each electronic component 25 to the housing 11 moves from the second region 112 toward the first region 111.

At this time, as shown in FIG. 11, if the positions of the two electronic components 25 overlap in the Y direction within the plane of the first board 21, the heat transferred from one electronic component 25 to the casing 11 A movement path R1 that moves from the second area 112 toward the first area 111, and a movement path that moves the heat transferred from the other electronic component 25 to the casing 11 from the second area 112 toward the first area 111. R2 joins (interferes with), and heat cannot be transferred smoothly. On the other hand, in the sixth embodiment, as shown in FIG. 10, the two electronic components 25 are arranged in parallel so that the positions of the two electronic components 25 do not overlap in the Y direction within the plane of the first substrate 21. It is located in Therefore, the heat transferred from one electronic component 25 to the casing 11 is transferred from the second region 112 toward the first region 111 along the movement path R1, and from the other electronic component 25 to the casing 11. The movement path R2 along which heat moves from the second region 112 toward the first region 111 is transmitted to the heat radiation fins 61 without merging (interfering) in the middle in the X direction. Therefore, the heat generated by each electronic component 25 can be quickly transferred to the heat radiation fins 61 through the movement paths R1 and R2.

Note that in the sixth embodiment, the arrangement of the two electronic components 25 mounted on the first substrate 21 has been described, but the present invention is not limited to this. Regarding the arrangement of the component 25, the electronic component 24 mounted on the second board 22, and the electronic component 26 mounted on the third board 23, the positions are shifted in the Y direction and arranged in parallel in the same manner as described above. Good too. Further, the number of electronic components arranged in parallel is not limited to two, but may be three or more.

<Modified examples, etc.>
The present invention is not limited to the embodiments described above, but includes various modifications. For example, in the embodiments described above, the content of the present invention is explained in detail to make it easier to understand, but the present invention is not necessarily limited to having all the configurations described in the embodiments described above. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. Furthermore, it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete some of the configurations of each embodiment, add other configurations, or replace them with other configurations.

For example, in the embodiments described above, an electronic control device used in an automobile (electronic control device for a vehicle) was explained as an example, but the electronic control device according to the present invention can be used for purposes other than automobiles. I don't mind.

DESCRIPTION OF SYMBOLS 11... Housing, 15, 16... Hole, 21... First board, 22... Second board, 23... Third board, 24... Electronic component (PCIeSW), 25... Electronic component (SoC for image processing) , 26... Electronic component (accelerator), 31... BtoB connector (second BtoB connector), 32, 33... BtoB connector (first BtoB connector), 41... first cover, 42... second cover, 51 ...Fan, 52...Fan cover, 52b...Fin, 85...Heat pipe, 91...Waterproof material, 100...Electronic control device, 111...First region, 112...Second region

Claims (15)

A casing that has a first region in which heat dissipation fins are formed on one side, an electronic component that generates the largest amount of heat is in thermal contact with the other side, and a second region in which the electronic component is in thermal contact with one side and the other side. An electronic control device with a body. a first substrate on which electronic components are mounted that are in thermal contact with one side of the second region;
a second substrate on which electronic components are mounted that are in thermal contact with the other side of the second region;
The electronic control device according to claim 1, wherein the first board is fixed to one side of the casing, and the second board is fixed to the other side of the casing. a first BtoB connector connecting the first board and the second board;
The housing is formed with a hole for inserting the first BtoB connector,
The electronic control device according to claim 2, wherein the longitudinal direction of the hole is formed to be substantially parallel to the arrangement direction of the first region and the second region. a third board on which the electronic component that generates the largest amount of heat is mounted;
a second BtoB connector connecting the second board and the third board,
The second BtoB connector is provided on a surface of the third board on which the electronic component with the largest amount of heat is mounted, and on a surface of the second board on which the electronic component is mounted. 3. The electronic control device according to 3. The electronic component mounted on the third board and generating the largest amount of heat is an accelerator,
The electronic component mounted on the first board is an image processing SoC,
The electronic control device according to claim 4, wherein the electronic component mounted on the second board is a PCIeSW. The accelerator and the second BtoB connector are mounted on the same surface of the third board by BGA,
The PCIeSW, the second BtoB connector, and the first BtoB connector are mounted on the same surface of the second board by BGA,
6. The electronic control device according to claim 5, wherein the image processing SoC and the first BtoB connector are mounted on the same surface of the first board using a BGA. an air cooling fan provided on the fin side of the first region;
The electronic control device according to claim 6, further comprising a fan cover provided to cover the radiation fin. 8. The first connector provided on the first board and the second connector provided on the second board are arranged on the same side of the side surface of the casing. Electronic control unit. a first cover provided to cover an opening on one side of the housing;
a second cover provided to cover the opening on the other side of the housing,
The first board is arranged in a space formed by the casing and the first cover,
The second board and the third board are arranged in a space formed by the casing and the second cover,
The electronic control device according to claim 8, further comprising a waterproof material that fills gaps between the casing, the first cover, the second cover, the first connector, and the second connector. The casing has a recess,
The electronic control device according to claim 1 or 4, wherein the electronic component is arranged in the recess. The electronic control device according to claim 10, wherein a gap formed between the recess and the electronic component is filled with a heat dissipation material. The electronic control device according to claim 7, wherein the fan is provided at an end of the radiation fin. The electronic control device according to claim 1 , further comprising a heat pipe that is in thermal contact with the electronic component and the radiation fin. The electronic control device according to claim 7, wherein a fin is formed on the fan cover. At least two of the electronic components are mounted on the first board,
The electronic control device according to claim 2, wherein the at least two electronic components are arranged in parallel with respect to the arrangement direction of the first region and the second region.

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